San Carlos weather in October

In October, San Carlos sees average daytime highs of 71°F and overnight lows near 54°F, with 0.9 in of rain across 3 wet days and about 11 hours of daylight. It is the 4th-warmest and 7th-wettest month of the year here.

Highs ease over the month, from about 73°F in the first days to 68°F by the end. The sky is clear or mostly clear about 62% of the time in October, and the air most often feels dry.

Daylight stretches from about 11 h 36 min at the start of October to 10 h 30 min by month's end. Set against the rest of the year, October is San Carlos's 5th-clearest and 12th-windiest month. For the whole year in context, see San Carlos's year-round climate.

Daytime high
71°
4th warmest
Overnight low
54°
9th coldest
Rainfall
0.9 in
3 wet days
Daylight
11 hours
6:24 AM – 5:25 PM
Cloud cover
33%
5th clearest
Wind
4 mph
12th windiest
Solar energy
4.23 kWh/m²
Travel score
8.2
out of 10

San Carlos is city in San Mateo County, California, United States.

Density
2,096/km²
people per km²
Founded
1925

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in October

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 73°F in the first days to 68°F by the end.

A typical October day in San Carlos reaches about 71°F in the afternoon and slips back to 54°F overnight — a 16°F spread between the day's warmth and the night's chill. On most days the high lands between 63°F and 81°F. Set against its neighbours, October runs about 3°F cooler than September and about 8°F warmer than November.

40°50°60°70°80°151015202531
Avg high (°F)Avg low (°F)
17356
27356
37356
47356
57356
67355
77355
87355
97255
107255
117255
127255
137255
147255
157155
167154
177154
187154
197154
207054
217054
227054
236953
246953
256953
266953
276853
286853
296853
306752
316752

San Carlos weather by month

How October compares with the rest of the year at a glance. October is the 4th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan57° / 45°3.99.49.74.1
Feb59° / 47°4.29.310.64.5
Mar61° / 48°3.29.111.75.3
Apr63° / 49°1.65.612.96.4
May66° / 52°0.83.3147.4
Jun70° / 54°0.20.914.58.5
Jul73° / 56°0.00.214.39.1
Aug74° / 57°0.00.113.49.2
Sep74° / 57°0.10.412.39.2
Oct71° / 54°0.93118.2
Nov63° / 49°2.06106.1
Dec57° / 46°3.79.39.54.1

Cloud cover in October

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 62% of the time in October.

Beyond those clear spells, partly cloudy skies cover about 14% of October, with mostly cloudy or overcast conditions the remaining 25%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
18317
28317
38317
48119
58119
68020
78020
87921
97822
107723
117723
127723
137624
147525
157525
167525
177525
187426
197426
207327
217327
227327
237327
247327
257327
267228
277129
287030
297030
306931
316832

Chance of precipitation in October

Any precipitation

San Carlos gets around 0.9 in of rain over 3 wet days in October. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 9% and peaks near 16% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%151015202531
Rain chance (%)
15
25
35
45
56
66
76
87
97
107
117
127
137
148
158
168
179
189
1910
2010
2111
2211
2312
2412
2513
2613
2714
2814
2915
3015
3116

Humidity in October

DryComfortableHumidMuggyOppressiveMiserable

Most of October feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, October lands in the dry band about 79% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
169292
271281
372271
473261
574251
675241
776231
877221
976222
1077212
1177212
1277212
1377212
1477212
1577212
1678211
1779201
1879201
1979201
2080191
2180191
2281181
2382171
2482171
2583161
2683161
2784151
2885150
2985150
3086140
3186140

Wind in October

Winds average 4 mph in October, the calmest month.

Across October, daily wind ranges from about 4 mph on the calmest days to 4 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
14calm
24calm
34calm
44calm
54calm
64calm
74calm
84calm
94calm
104calm
114calm
124calm
134calm
144calm
154calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm
314calm

Sunrise & sunset in October

DaylightNight

Daylight runs from about 11 h 36 min at the start of October to 10 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 66 minutes over October. Sunrise moves from 6:09 AM to 6:39 AM, and sunset from 5:47 PM to 5:06 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.66:095:47
211.66:105:45
311.56:115:44
411.56:125:42
511.56:135:40
611.46:145:39
711.46:155:37
811.36:165:36
911.36:175:34
1011.36:185:33
1111.26:195:32
1211.26:205:30
1311.16:215:29
1411.16:225:27
1511.16:235:26
1611.06:245:25
1711.06:255:23
1810.96:265:22
1910.96:275:21
2010.96:285:19
2110.86:295:18
2210.86:305:17
2310.76:315:15
2410.76:325:14
2510.76:335:13
2610.66:345:12
2710.66:355:11
2810.66:365:10
2910.56:375:08
3010.56:385:07
3110.56:395:06

Solar energy in October

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in October, about 4.23 kWh/m².

For context, solar energy here swings from a low near 2.27 kWh/m² to a high of 7.76 kWh/m² in June across the year — October's 4.23 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.0Bright
25.0Bright
34.9Bright
44.9Bright
54.8Bright
64.8Bright
74.7Bright
84.7Bright
94.6Bright
104.5Bright
114.5Bright
124.5Bright
134.4Bright
144.3Bright
154.3Bright
164.2Bright
174.2Bright
184.1Bright
194.1Bright
204.0Bright
214.0Moderate
223.9Moderate
233.9Moderate
243.8Moderate
253.8Moderate
263.7Moderate
273.7Moderate
283.6Moderate
293.6Moderate
303.5Moderate
313.5Moderate
Planning a trip in October

Hazard calendar for San Carlos

In seasonPeak

None of San Carlos's seasonal hazards are active in October. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

San Carlos's rainy season runs November–March, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is October a good time to visit San Carlos?

Our two travel scores rate October for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

8.2
Sightseeing
5th-best month of the year
5.3
Beach & pool
4th-best month of the year

October is one of the better times to visit San Carlos for general sightseeing.

What to pack for San Carlos in October

From October's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In October, San Carlos sees daytime highs around 71°F and nights near 54°F. Little to plan around — just the basics. About 3 days see rain.

Sea temperature near San Carlos in October

The nearest coast averages about 58°F in October — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 11 mi away) is warmest in August at about 59°F and coldest in April near 54°F.

The water stays below 68°F all year — cool enough that most swimmers want a wetsuit.

52°54°56°58°60°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°F)Comfort
Jan54Bracing
Feb54Bracing
Mar54Bracing
Apr54Bracing
May54Bracing
Jun55Bracing
Jul57Bracing
Aug59Bracing
Sep59Bracing
Oct58Bracing
Nov56Bracing
Dec55Bracing

UV index in San Carlos in October

LowModerateHighVery highExtreme

Clear-sky midday UV in October peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in San Carlos peaks around June 23 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJun 23UV 10Dec 15UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar5Moderate
Apr6High
May8Very high
Jun10Extreme
Jul10Extreme
Aug10Very high
Sep6High
Oct5High
Nov2Moderate
Dec2Moderate

Air quality in San Carlos in October

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where October falls, not just the annual average.

Air quality in San Carlos is worst in August — around 25 µg/m³ PM2.5 (moderate), about 2.5× the cleanest month (June, 10 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateAug 1824 µg/m³Jun 1110 µg/m³
PM2.5 (µg/m³)Level
Jan15Moderate
Feb18Moderate
Mar16Moderate
Apr12Moderate
May10Good
Jun10Good
Jul11Good
Aug25Moderate
Sep17Moderate
Oct20Moderate
Nov18Moderate
Dec13Moderate
Location & terrain

Where is San Carlos?

San Carlos sits at 37.5°N, 122.3°W, 33 ft above sea level, in United States. The nearest listed city is Belmont, 1.2 mi away.

Topography around San Carlos

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of San Carlos.

Within 2 miles, the terrain around San Carlos has significant variations in elevation — a maximum elevation change of 902 ft around an average of 121 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,454 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 4,452 ft.

The land around San Carlos is covered by artificial surfaces (50%) and trees (27%) within 2 miles, trees (39%) and water (33%) within 10 miles, and water (40%), trees (24%) and grassland (21%) within 50 miles.

2 miles
902 ft
10 miles
2,454 ft
50 miles
4,452 ft
treesshrubsgrasslandcroplandartificial surfacesbare terrainwaterwetland
October weather nearby: Belmont 1.2 mi · Redwood City 1.9 mi · Foster City 3.7 mi · San Mateo 5.0 mi · Menlo Park 5.6 mi · East Palo Alto 6.8 mi · Burlingame 8.1 mi · Palo Alto 8.1 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for San Carlos (37.5072°, -122.2605°, elevation 33 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).